History of the Stovebolt 6 Engine

horsepower | casting codes | head-bolt patterns | side/valve covers

1954Advance-Design.com

1929-1962
Chevrolet L-6 (straight/in-line 6) Overhead Valve Engines

the Stovebolt Six - the Cast-Iron Wonder
head-bolt patterns,
torque settings

most of the information below was obtained from Shop Manuals
194, 181, and 207 photo was provided by Fred Nixon

 

207-181-184-head


First Generation 1929-1936

Low-Pressure Oil (internal lubrication) System

Year
Truck & Pass
- head-bolt pattern
Truck
- head-bolt pattern
Truck
- head-bolt pattern
1929
194 c.i.
above pattern




1930
194 c.i.
above pattern




1931
194 c.i.
above pattern




1932
194 c.i.
above pattern




1933
194 c.i.
above pattern




1934
194 c.i.
above pattern


207 c.i.
above pattern
1935
194 c.i.
above pattern
181 c.i.
above pattern
207 c.i.
above pattern
1936
194 c.i.
above pattern
181 c.i.
above pattern
207 c.i.
above pattern

 

pattern#1 216/235

Second Generation 1937-1953

Low-Pressure Oil (internal lubrication) System

Year
Truck
& Pass
- head-bolt pattern
Truck
- head-bolt pattern
Pass
- head-bolt pattern
1937
216 c.i.
- pattern 1 (75-80 ft-lbs)




1938
216 c.i.
- pattern 1 (75-80 ft-lbs)




1939
216 c.i.
- pattern 1 (75-80 ft-lbs)




1940
216 c.i.
- pattern 1 (75-80 ft-lbs)




1941
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1942
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1943
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1944
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1945
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1946
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1947
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1948
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1949
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)


1950
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)
1951
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)
1952
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)
1953
216 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.
- pattern 1 (75-80 ft-lbs)
235 c.i.1
- pattern 2 (90-95 ft-lbs)

 

note 1: The 1953 Powerglide-equipped passenger car engine was the first 235 engine with the high-pressure oil system. This engine used a head with the later bolt pattern (pattern 2). It used the earlier, 2-bolt valve cover and had the short side cover, same as the 1950-1953 235 truck and 1954-1962 235/261 side covers (it did not cover the spark plugs).

 


 

pattern #2 late 235

pattern #32 261

Third Generation 1954-19622
High-Pressure Oil System (internal lubrication)

Year
Pass
- head-bolt pattern
Truck
- head-bolt pattern
Truck
- head-bolt pattern
1954
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)
1955
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)
1956
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)
1957
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)
1958
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)
1959
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)
1960
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)
1961
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)
1962
235 c.i.
- pattern 2 (90-95 ft-lbs)
235 c.i.
- pattern 2 (90-95 ft-lbs)
261 c.i.
- pattern 3 (90-95 ft-lbs)

 

note 2: There is a special drilled bolt that is used when a 1959-62 block is used with an earlier head and the 59-62 rocker arm assembly, to reduce the oil flow to the rockers. This bolt is used with the drilled-bolt Plug # 37 64 579 that is installed in the block oil-port near the right center head bolt. This plug blocks the original oil path and sends it through the drilled head bolt (posted by Pre '68 Dave, on The Stovebolt Page forums).

note 3: The design of the lifters changed in 1958, due to a new oiling path from both ends of the camshaft into/through the lifter jourbals. Itr is imperative that these new lifter (that have a annular ring) be used in the 1958-1962 blocks.

note 4: The 54-62 235 and 261 c.i. heads had the same bolt pattern, but the Inliners International Tech Tip on head-bolts states that the tightening sequences are different.

note 5: The 261 c.i. head has extra coolant holes between cylinder-pairs; these holes may be drilled into the 1954-1962 235 heads, for use on a 261 c.i. block (the photo below is from the Jim Carter Antique Truck Parts, Tech Article on the 261 c.i. engine).

261 water passages


History of the Stovebolt 6 Engine

horsepower | casting codes | head-bolt patterns | side/valve covers

1954Advance-Design.com

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